Question 747330
If you want to average 77, your total points will need to be:

{{{77*5}}}
{{{385}}}

Averaging 76 on four tests, gives you a running total of 

{{{76*4}}}
{{{304}}}

Subtract 304 from 385 to give you the score you'd need.

{{{385-304}}}
{{{81}}}